May 28, 2020 - 07:30 AM
It's usually used as a topper, but that's not a rule. I would be careful with polyester bobbin thread if you use on the wrong side (or if you used poly on the top). Do a test first if you don't use rayon or cotton thread to be sure your iron is set at a temperature that will remove the Heat-Away but not melt the thread. Poly will melt before rayon will.